The present invention has relevance in connection with a lock specifically intended for the bulk vending machine type apparatus. A bulk vending machine is generally the type which has a hopper or a product container, into which a vendible product is loaded. The product is vended usually by means of a coin mechanism to the ultimate user. In operation, the vending machine will have a hopper enclosed by a top cap, which, when removed, affords the operator access to the hopper or container. The operator then loads the vendible product into the hopper, and encloses it by placing the cap on the top of the hopper and locking the same into position. In this manner, the machine is ready for operation to vend product in response to a coin inserted in the coin mechanism by the ultimate consumer.
It will be appreciated that machines of this type are extremely prevalent, for vending products such as candy, gum, and other bulk vended products. It will also be appreciated that in order to load the hopper with vendible product as well as empty the coinage from the machine, there are usually route operators that will go from machine to machine with the necessity that the machines be loaded with additional product, and that the money be removed.
Typically, the cap is kept into an engaged position on top of the hopper, by means of a lock. The lock typically has a keyway which accommodates a key to be inserted therein and the typical lock is a screw threaded lock meaning that the lock screws onto a threaded rod which extends upwardly in the interior of the hopper. The lock, which is centrally positioned in the cap, has a threaded collar which threads onto the upper threaded portion of the hopper rod, and this is accomplished by turning the key multiple times in order to thread the lock onto the treaded rod. It is also noteworthy that the method of removal of the money from most of such bulk vending machines is that the cap must be removed, the entire hopper assembly removed from the base, in order to gain access to the coinage which is located in a coin box below the hopper. Hence, the cap must be removed from the hopper regardless of whether the operator wishes to fill the hopper with additional product, or remove the coinage.
It will be appreciated that where the operator or route man has numerous machines per day to either fill with product, or empty coinage, the operation of twisting a lock in a counter clockwise direction to remove the cap, and then reinserting the cap by screwing the cap in a clockwise direction and doing that numerous times per day is tedious and cumbersome. It has therefore been deemed desirable to create a lock which will lock the cap to the hopper of a bulk vending machine requiring no more than a quarter turn in order to eliminate the tedious rotation movement presently necessary.
The prior art shows various lock assemblies which are designed to engage and lock one element to another employing a one quarter turn of the lock. For example, U.S. Pat. No. 3,415,086 shows a lock and bayonet connector for locking an automobile hood to the body. The lock is provided with a lower stud having a t-shaped cross pin which engages a slotted bolt head. The slotted bolt head includes a first slot which extends vertically and is adapted to receive the t-shaped cross pin. The slot then turns 90° and allows the cross pin to lock in the horizontal slot.
It has been determined that a lock device of this design will not operate properly to lock a cap to a bulk vending machine hopper. The cap covering the hopper must be progressively drawn down to tightly cover the hopper and prevent any unauthorized entry as well as preventing anyone from inserting a contaminate in the hopper, since the hopper often contains food product. The only requirement of the lock shown in the -086 patent is to lock the hood to the automobile body. Hence, some degree of play is allowed as between the hood and the body.
Various other prior art patents show locking devices which engage one element to another by engaging a lock bar and pin in a curvilinear slot. U.S. Pat. No. 3,600,018 shows an automobile hood lock consisting of an upstanding slotted stud mounted to the automobile body which receives a cross pin carried in a spring loaded lock carried by the hood. The spring is required in that once the pin enters the curvilinear slot; the urging action of the spring keeps the pin engaged in the slot. To uncouple the lock, the operator inserts the key and pushes down against the urging of the spring as the lock is turned to remove the cross pin from the slot.
This design has been unsuitable for a bulk vending device for numerous reasons. Bulk vending machines are generally manufactured with a glass hopper so that the purchasing consumer can view the product in the hopper. The cap or lid is formed from a formed metal plate which is designed to seat over and tighteningly engage the hopper. As such, there is no flex or play in either the cap or the hopper to allow a lock to be pushed downwardly in order to commence engagement of the lock components. Therefore, the lock assembly cannot include any spring loaded component. The lid cannot be pushed downwardly since pushing against the lid may possibly deform the metal and result in damage to the lid and the inability of the lid to properly enclose the hopper.
Another fastening device as shown in U.S. Pat. No. 4,653,970 which accommodates a one-quarter turn lock. In this design, a locking stud is provided with an angled slot which is adapted to receive a locking bar therein. The slotted stud is pushed downwardly and turned so that the locking bar travels into the angled slot until the locking bar travels into opposed undercuts in the slot such that the locking bar will be retained in the slot. Once again, a spring is employed so that the slotted stud may be pushed downwardly to commence the unlocking sequence in order to unseat the locking bar from the undercuts.
As has been previously described, the existing design of the bulk vending machines do not allow any flex or play as between the cap and the hopper. Hence, a lock which includes an angled slot with undercuts and a lock pin which engages in the slot will not be suitable for bulk vending machines. It will be apparent that if the slot includes undercuts to engage the pin in the slot, a spring device of some type must be incorporated in the lock in order to permit disengagement of the locking pin from the undercuts in order to commence the unlocking sequence.
Similar comments are applicable to the fastening device shown in British patent 1,242,196. The lock shown in this patent, once again shows a slotted stud designed to engage a stationary lock. However, the lock pin remains in the locked or engaged position by being captured in opposed undercuts. Once again a spring is incorporated in the lock as previously described, to facilitate the unlocking sequence, as shown in FIGS. 10 and 11 of the British patent.
In co-pending application Ser. No. 11/407,834, a lock assembly was designed for particular application to a bulk vending machine. As is well known, bulk vending machines are formed with a glass hopper which contains the vendible product, and a cap which encloses the hopper. The hopper includes an upstanding stud centrally located in the hopper which has a threaded upper end. The cap is provided with a centrally positioned lock carried in a central aperture formed in the cap. As was previously described, the presently existing locks are provided with a lower threaded collar which is designed to seat onto the threaded hopper rod. Locking is achieved by placing the key in the cap lock and turning the threaded collar to engage the threaded rod, necessitating several turns of the lock to complete the locking sequence and to do likewise to unlock the cap from the hopper.
In the above co-pending application, a lock post is provided which is fixedly secured to the threaded rod. The lock post is provided with a slot adapted to receive a lock pin therein. The cap lock is provided with a lock collar secured to the lower end of the lock barrel and includes a lock pin secured within the confines of the lock collar.
The slot formed in the lock post is designed to receive the lock pin in a centrally positioned diametric slot or channel and then angled downwardly such that as the lock is turned by an appropriate key, the lock pin travels down the angles slot to a locked position.
The lock post is designed with an upper tubular portion and a lower nut portion which threadedly engages the threaded hopper rod.
However, it has been determined that the lock post formed with a lower nut portion for engaging the threaded hopper rod poses a difficulty in that it is difficult to operate a tightening tool to engage and tighten the nut onto the threaded hopper rod. In many instances, the space afforded within the interior of the hopper restricts the use of most common tightening tools such as a wrench. As a result, operators have used a flat head screwdriver to tighten the lock post onto the threaded rod. It has been found that operators insert the flat-head screwdriver into the center diametric channel and hence tighten the lock post onto the rod. However, in doing so, the screwdriver tends to damage the dimensions of the slot or channel which results in compromising the locking engagement of the lock pin in the angled channel. It was also determined that in order to fully tighten and draw the cap to the hopper, that is, to its fully closed position, the configuration of the angled channel must assume certain requirements. Hence, the combination of the improper installation methods as well as the configuration of the angled channel, compromises the locking capability of the lock assembly.
The lock assembly of the present invention now provides a lock which permits ease of installation while providing a design that will positively draw the cap tightly down to the hopper, and lock the same in position with a 90° turn of the key in the lock.